A vulnerability in the Network Configuration Access Control Module (NACM) of Cisco IOS XE Software could allow an authenticated, remote attacker to obtain unauthorized read access to configuration or operational data. This vulnerability exists because a subtle change in inner API call behavior causes results to be filtered incorrectly. An attacker could exploit this vulnerability by using either NETCONF, RESTCONF, or gRPC Network Management Interface (gNMI) protocols and query data on paths that may have been denied by the NACM configuration. A successful exploit could allow the attacker to access data that should have been restricted according to the NACM configuration. Note: This vulnerability requires that the attacker obtain the credentials from a valid user with privileges lower than 15, and that NACM was configured to provide restricted read access for that user.